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#1
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![]() "Art Unwin" wrote in message ... On Mar 7, 11:19 pm, (Richard Harrison) wrote: Art wrote: "No where can I find reference to "size" in what the masters state." It`s there if you look. Kraus is a certified master. In the newest edition, the 3rd, of "Antennas" is found on page 12: "The basic equation of radiation may be expressed simply as IL=QV, where I=time changing current L=length of current element Q=charge,C V=time change of velocity or acceleration Thus, time changing current radiates and accelerated charge radiates. For steady-state harmonic radiation, we usually focus on current. For transients or pulses, we focus on charge." The above is the beginning of the chapter on "Antenna Basics". Everyone interested in antennas needs ready access to this important book. Best regards, Richard Harrison, KB5WZI But you arer forgettfull Richard, my antenna is a full wavelength which meets Maxwells requirements, it is just that the volume is small despite the wavelength. It is also not in conflict with "antenna basics" alluded to above. I don't understandwhat the beef is. Why are so many hams alarmed at the idea? Regards Art its called 'experience' by most and 'knowledge' by those in the know. |
#2
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Art wrote:
"---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI |
#3
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On Mar 8, 10:21 am, (Richard Harrison)
wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI There are no loads on my antenna so your statements are irrelavent Art |
#4
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On Mar 8, 11:21 am, (Richard Harrison)
wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI Considering that it meets Maxwells requirements and is at least a wavelenght of a radiator my expectations are much higher than yours I suspect that the output will exceed that of a 160 M antenna which has a ground plane. I also suspect that if I diddn't concentrated so much on small physical size it could easily be uprated to compete with a yagi! I would anticipate that in a couple of years the top band will have twice as many users that it has now. I am hoping also that its small size will allow for receiving abililities in line with the angle of incoming radiation via its manouvarability. Of course if all is already known about radio this would seem impossible but in a few weeks I myself will have a few QSOs to see how it matches up to my expectations. The archives show all the building instruction but it appears that readers have concentrated on nonsensical retorts without reading the content. If an antenna is at least off one wavelength and is in equilibrium I see no reason why it should not beat existing antennas with ground plane losses regardless of its shape or size. Time will tell. Either way the experimental trail undertaken I have found to be very rewarding as many other amateurs have had when experimenting with antennas and who refuse to accept that all is known Art |
#5
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Art,
"Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc |
#6
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On Mar 9, 7:16 am, wrote:
Art, "Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc You may be right We will just have to wait and see how things turn out. If it works then I am smart and if it is useless then I fit what everybody thinks of me. No damage done either way. |
#7
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On Mar 9, 9:23 am, Art Unwin wrote:
On Mar 9, 7:16 am, wrote: Art, "Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc You may be right We will just have to wait and see how things turn out. If it works then I am smart and if it is useless then I fit what everybody thinks of me. No damage done either way. My replacement antenna for the one I sent away is comming along just fine and I will probably be active on the air in a few weeks. The new one is about two shoe box size and will be connected to a tilt/ scan mechanism so that I can fully determine all the characteristics in real life circumstances. The frequency spread is down to the top of the broadcast band and it will be controlled by my Icom where I will disconect the inbuilt tuner motors and reconnect to my antenna. This should then ensure that the antenna is always in equilibrium screw driver style when I am on the air regardless of the band in use.Hoping to change polarity in QSO's to investigate the differences. Hopefully this summer the pan tilt will also be made automatic for best polarity reception which will then allow for the addition of a dish reflector. Bought myself a new thin Mac laptop which is exciting to use. There is a free NEC 2 program available(cocoanec) so it is getting difficult to determine what to work on. Spring is coming and life is good despite the naysayers. Have a happy day Regards Art |
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